Drip irrigation systems have come into widespread use in the agricultural area. Drip irrigation systems supply water at a slow, controlled rate to the root zone of the particular plants being irrigated. Typically, drip irrigation is accomplished by providing a low volume water outlet at each plant that permits a limited dripping of water directly to the root zone of the particular plant. Because evaporation, runoff, overwatering, and watering beyond the root zone are eliminated, substantial water and nutrient savings are realized. In addition, drip irrigation reduces contaminants to the water table by enabling the farmer to supply only enough water and fertilizer to reach the plants, reducing excess water that would run off and contaminate the water table below.
Drip irrigation may be supplied by hoses having drip emitters built into the hose at manufacture. These are configured to cause a reduction in water pressure between the water in the hose, and water at an outlet of the emitter. Other systems have been developed in which a user may insert separately manufactured drip emitters into the hose at spaces that are more suited to the local environment and needs for irrigation. However, as the water travels along the hose away from the water source, the pressure of the water decreases. Thus, the water pressure at the beginning of the hose (near the water source) is greater than that at the far end of the hose. Because the drip rate of an emitter is a function of the water pressure, the drip rate at the beginning of the hose may tend to be greater than at the end of the hose. Other field conditions, such as elevation, also affect the pressure, and thus the drip rate, along the length of the hose. However, it is often desirable to have a relatively uniform drip rate along the length of the hose. Moreover, other varying field conditions, such as soil type and drainage, create a need to have different drip rates throughout the field to compensate for the different field conditions.
Thus there is a need in the field of drip irrigation for a versatile system that a user may adapt to the changing needs of the environment, and to the location of the emitter along the length of a hose, to create a desired drip flow profile. The present invention addresses these and other needs.